/**
 * #      1315
 * 名称   祖父节点值为偶数的节点和
 * 链接   https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent
 * 题解   [208](https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent/solution)
 * 通过率 81.0%
 * 难道   中等
 */

